Kevin Maguire is one of the journalists closest to new prime minister Gordon Brown. As such, we can also expect him to be one of the best informed.

Described by one Labour MP as the "cheekiest and best informed [journalist] about Labour's politburo manoeuvres", the Daily Mirror columnist and associate editor (politics) is rarely off our screens or Radio Five Live talking about the latest political developments.

"He will get more scoops now Gordon Brown is PM," said one of our panellists. "He may well become Brown's Alastair Campbell."

However, Brown has adamantly denied that he would follow in Campbell's footsteps by becoming the next Downing Street spin doctor.

The former chief reporter on the Guardian, Maguire joined the Mirror in 2004. One of editor Richard Wallace's first star signings, he returned to the paper he quit in 1999 after a fallout with its previous editor, Piers Morgan.

Maguire's first stint at the Mirror lasted five years and won him an award in 1997 for his story that BSE could be transferred to humans. He was nominated for political journalist of the year at this year's British Press Awards.

Not all of our panel thought Maguire should be included in this year's list, with some arguing his influence might be lessened now that Brown has got the top job.

"It is much easier to be critical and get someone into power than it is to defend them once they have got that power," said one panellist. "I think he may lose his bite."

Maguire said Brown's arrival at No 10 could coincide with a new era in the government's relationship with journalists.

"I think it will allow him to enter a period where politics is a bit more serious, which plays to Brown's strengths," he told the Guardian.

"If David Cameron is aping Blair, and will do stunts like pose on bicycles or with huskies, Brown can define himself against Cameron as being a more substantial political figure.

"[Brown's team] have also learned from Blair's mistakes, such as handing stories to favourite newspapers, like the Sun and the Times, which means the other papers then turn on them. They now know that they have to deal with the media more even-handedly."

· To contact the MediaGuardian newsdesk email editor@mediatheguardian.com or phone 020 7239 9857. For all other inquiries please call the main Guardian switchboard on 020 7278 2332.

· If you are writing a comment for publication, please mark clearly "for publication".